1. Field of the Invention
Methods consistent with the present invention relate to a method of fabricating a high resolution electric field sensor having an electric field shield.
2. Description of the Related Art
In order to increase the information storing capacity, a probe should detect surface charges present in a small region of a few tens of nanometers in an information storage medium. Such probe can be applied to a scanning probe microscopy and a hard drive.
FIG. 1 is a cross-sectional view of a cantilever 70 having a related art resistive tip 50 as disclosed in International Patent Publication WO 03/096409. A resistive tip 50 is formed vertically on the cantilever 70. The resistive tip 50 may have a diameter of a few tens of nanometers and a number of cantilevers 70 may be arranged in array.
Referring to FIG. 1, the resistive tip 50 includes a main body 58 doped with a first impurity. A resistance region 56 is located on an apex portion of the resistive tip 50 and is doped with a low concentration of a second impurity, and first and second semiconductor electrode regions 52 and 54 which are located on both side slopes of the main body 58 and are doped with a high concentration of the second impurity.
However, in the semiconductor probe having the related art resistive tip 50, the regions of the slopes of the first and second semiconductor electrode regions 52 and 54 doped with a high concentration are reduced by excessive etching during a wet etching process for forming the resistive tip 50. Accordingly, the first and second semiconductor electrode regions 52 and 54 may have the characteristic of the resistance region 56 due to the reduction of the conductive regions on the slopes. Therefore, the spatial resolution to resistance variation can be reduced.
Meanwhile, to increase the spatial resolution of the semiconductor probe, research on a semiconductor probe having an electric field shield on the slope of a resistive tip has been conducted to prevent the first and second semiconductor electrode regions 52 and 54 from having the characteristics of the resistance region 56. However, it is difficult to align an opening of the electric field shield on the tip of the semiconductor probe in a process of manufacturing the semiconductor probe having the electric field shield. Also, it is difficult to form a diameter of the opening of the electric field shield to have a constant size.